1. Field of the Invention
The present invention relates to a liquid crystal display device and a method of fabricating the same, and more particularly, to a liquid crystal display device with a sensing function and a method of fabricating the same.
2. Discussion of the Related Art
A liquid crystal display device includes a color filter substrate provided with a color filter and a black matrix; a thin film transistor array substrate provided with a thin film transistor used as a switching unit and a pixel electrode; and a liquid crystal layer formed by injecting a liquid crystal material having an anisotropic dielectric constant into a space between the color filter substrate and the thin film transistor array substrate. A different electric potential is applied to the electrodes on the substrates. The intensity of a resulting electric field formed in the liquid crystal material can be controlled to thereby change alignment of liquid crystal molecules in the liquid crystal layer. Through the change in alignment of the liquid crystal molecules, it is possible to control an amount of light passing through a transparent insulation substrate, thereby displaying desired images.
The liquid crystal display device does not itself emit light. Therefore, it is necessary to provide the liquid crystal display device with a backlight unit. The backlight unit is provided at the rear surface of liquid crystal panel to display images, so that an entire screen is illuminated uniformly with the light emitted from the backlight unit. Based on a structure of the thin film transistor array substrate, the liquid crystal display device can be classified into a display function and a sensing function (touch sensor, fingerprint sensor, etc.).
In the case where the liquid crystal display device has a sensing function, each pixel region is provided with a sensor driving circuit. The sensor driving circuit formed in each pixel region is provided with a light-shielding region, which prevents the incidence of light generated from the backlight unit.
Due to the sensor driving circuit with the light-shielding region in each pixel region, a light-transmission region, which permits the incidence of light generated from the backlight unit, is decreased in size.
Thus, the entire luminance of the liquid crystal panel is decreased.
Also, a liquid crystal display device with the sensing function includes the sensor driving circuit as well as the switching unit, so that a power consumption of the liquid crystal display panel is increased.